The present invention relates in general to electrical switch mechanisms, and in particular to a multiposition speed selector switch assembly actuated by interchangeable cleaning attachments coupled to the suction motor housing of a domestic vacuum cleaner.
Multifunction vacuum cleaners having a plurality of interchangeable cleaning attachments and other work attachments, such as air driven tools, are known in the art. It is further known to provide such vacuum cleaners with an electrical switch mechanism responsive to the positioning and securing of each attachment on the housing of the suction motor. Without an attachment coupled to the housing, the electrical switch mechanism maintains an open circuit condition to preclude inadvertent energization of the suction generating motor. When an attachment is secured to the motor housing, the attachment engages and activates the switch mechanism to move it to one of two motor speed determining positions. For example, a carpet cleaning attachment requires low speed suction motor operation, while a hard surface cleaning attachment requires high speed motor operation.
U.S. Pat. No. 3,319,282, assigned to the assignee of the present invention and incorporated in its entirety by reference herein, illustrates and describes a custom designed switch for performing the functions noted above. The disclosed switch is mounted on the external face of the suction motor housing engageable with associated attachments. While the '282 patent illustrates a switch mechanism having two separate actuating push buttons it is further known to utilize a single push button multiposition switch in place of the two push button switch illustrated.
It has been found that, while the switch illustrated in the '282 patent adequately performs the earlier noted functions, it is susceptible to infiltration by dirt and dust particles that can interfere with the electrical continuity between the switch contacts and with the mechanical movement of associated switch elements. Further, the noted prior art switch assembly, because of its custom design and complexity, is costly. Also, the switch elements which carry high current electric power are located on the exterior of the suction motor housing, thus being subjected to abuse wherein breakage of the switch housing could expose a user to an electrical shock hazard.